Apparatus for disintegrating and automatically screening coarse flowing matter carried in liquor



Jan. 19, 1960 K. STRENZ ETAL 2,921,583

APPARATUS FOR DISINTEGRATING AND AUTOMATICALLY SCREENING COARSB FLOWING MATTER CARRIED m LIQUOR Filed April 12, 1955 3 Sheets-Sheet 1 INVENTORS KARL STRENZ GEORG DANKESREITHER ATTORNEYS 2,921,683 CALLY SCREENING COARSE FLOWING MATTER CARRIED IN LIQUOR Filed April 12, 1955 Jan. 19, 1960 K. STRENZ EIAL APPARATUS FOR DISINTEGRATING AND AUTOMATI 3 Sheets-Sheet 2 v E E lllIl M m w m KARL STRENZ GEOBG DANKESREITHER W/%IMM ATTORNEYS Jan. 19, 1960 K. STRENZ EI'AL 2,921,683

APPARATUS FOR DISINTEGRATING AND AUTOMATICALLY SCREENING COARSE FLOWING MATTER CARRIED IN LIQUOR Filed April 12, 1955 3 Sheets-Sheet 3 hllll.

INVENTORS KARL STRENZ GEORG DANKESREITHER ATTORNEYS United States Patent APPARATUS FOR DISINTEGRATING AND AUTO- MATICALLY SCREENING COARSE FLOWING MATTER CARRIED IN LIQUOR Karl Strenz, Grossauheim, and Georg Dankesreither, Hanan am Main, Germany The present invention relates to a device capable of disintegrating floating matter carried in liquors, such as sewage, trade effluent, turbine propelling water, etc.

The solid floating matter contained in such liquors is reduced in such a manner that it can pass a screemng arrangement so to avoid contamination, clogging or similar operating troubles within sewers, valves, pumping stations, turbines, etc.

The novel mechanism of the present invention comprises a revolving drum screen consisting of several grates that are provided with slots staggered along the circumference of said drum. A plurality of combs form close fits with said slots, simultaneously grazing the surface of the drum screen and, consequently, the 'notches of the grate bars act as disintegrating tools.

Machines having only one comb on the peripheral area of the screening drum, the comb occuping the total vertical extension of the drum, have previously been proposed. The slotted drum of these conventional designs consists of a series of evenly spaced rings. The comb passes through the slots, each of them being formed by two adjacent rings. Also secured to the peripheral area of the drum are hook-shaped crushing teeth which pass through the cut-outs of the comb provided for this purose. p These prior art devices have numerous disadvantages, including the following:

(1) After some time of operation, the coarse floating objects accumulate in front of the only comb applied and thus clog the slots.

(2) As the revolving drum is unilaterally strained by the disintegrating force, .there is risk of the drum being injured in the course of time.

(3) The coarse sewage matter is reduced through only a single comb and, hence, the input power, having to be applied, is disproportionately high.

In addition to the objectionable features of the conventional designs described in the preceding paragraphs, there are further disadvantages which must be considered, including:

In the event the slotted drum is damaged by driftwood or similar bulky floating objects, it has to be put out of service and disassembled. This entails either a several days stoppage of the entire plant, or else, a number of complete drums have to be kept in stock as spares, or a coarse rack has to be installed to prevent large floating objects, such as beams, poles, boards, etc., from getting into the comminutor basin.

These and other objectionable features are eliminated by the novel apparatus of the present invention. The present modern device includes several combs that are spread over the drum area and pass through the drum slits or slots, simultaneously interacting with a number of disintegrating elements which are worked into the peripheral drum area. The comminuting effect is complete and unobjectionable, and virtually no backing-up or conglomeration of solids in front of the combs results. Furthermore, wires and similar metal objects slip oflf and drop to the bottom of the plant, whereas in all previous designs, cutters are inserted on the drum area only Within easy access to such metal pieces and, consequently, are readily subject to damage thereby. Moreover, in case the screens of my newly invented mechanism are damaged, exchange or repairs can be performed easily without necessitating dismantling of the entire drum screen. The present novel plant also offers advantages from the point of view of construction.

According to the present invention, the disintegrating elements on the drum area are composed of recesses, notches, etc.

The screening drum of the invention consists of several bar grates. If any of the bars are damaged, replacement is possible without the drum itself having to be disassembled. Rte-sharpening of the cutting edges of the disintegrating elements is also simple to accomplish.

As the slotted drum of the present invention is composed of a plurality of grates, it can be built in different sizes, i.e., with different vertical extension, without employing a special mold for each size.

Another advantage of the present apparatus is the ability to reverse the direction of rotation of the drum. When this is desired, the grates must be unscrewed from the supporting frame placed upside down and re-inserted. This constructional feature is of considerable value since, for example, when enlarging a sewer system, eventually additional drum screens have to be installed, frequently necessitating an inversion of the direction of rotation.

The invention may be more fully understood from the following detailed description with reference to the accornpanying drawings, wherein Figure 1 shows the complete installation for disintegrating and screening coarse sewage matter, etc., in vertical elevation;

Figure 2 is a sectional view showingthe developed peripheral area of the revolving drum including the special arrangement of the cutting elements;

Figure 3 is a detail sketch of part of the comminuter plant of Figure 1, showing a sectional of the screening drum and one of the columns bearing the combs;

Figure 4 is a sectional view along the line 44 of the drum screen in Figure 3;

Figure 5 is a plan view of a rib and related disintegrating elements of a bar grate accordin to my invention;

Figure 6 is a plan view of a bar grate constitutin one segment of the drum wall;

Figure 7 is a sectional view of the bar grate of Figure 6;

Figure 8 is a top plan view of a rib section; and

Figure 9 is a side view of a rib section.

In Figure 1, the comminutor, shown generally at 27, is installed into the sewer 1, having a wall 28, in such a manner that the waste liquor flows in accordance with directional markers A and B. The comminutor includes the casing 4 and the rotor or slotted drum indicated generally as 5, which comprises supporting arms 20 and a plurality of bar grates 11 each made of a plurality of grate bars 17 and longitudinal braces 25. The casing 4 comprises an upper part 6 and a bottom piece 7, connected by several vertical supporting columns 8. Atop the upper part 6, another smaller case 9 houses the electric driving motor (not shown). This protective covering 9 is provided with a ventilating shaft 10. The bar grates 11 of the drum screen 5 are held in place by several supporting arms 20. The several sets of combs 12 are secured to the supporting columns 8.

The interaction of the slotted drum 5 and the combs 12 is best illustrated in Figures 3 and 4. A special mounting bracket 14, holding the combs 12, is secured to the supporting column 8 by means of screws 13, whereas the combs themselves are fixed to said mounting bracket 14 by means of screws 15. As can be seen from Figure 4, each comb consists of a set of springs 29 provided with slotted holes. These springs are shiftable individually and, consequently, relatively to each other. They can be adjusted so as to obtain an inclined cutting edge 16 which is particularly eificient. The combs 12 pass through the grates 11. Preferably, at least six combs are used, although there can be employed as few as three combs.

The grates 11 comprising axially spaced grate bars 17, are secured to the supporting arms 20 of the rotor by means of screws 19 and are thus easily exchangeable. As is apparent from Figures 5 to 9, each bar 17 consists of a single piece which can be made, for example, of

cast metal, e.g., cast iron. The drum slots 21, which form a close fit with the combs 12, are formed by circularly curved grate bars 17, some of which are provided with recesses or notches 23 to create the cutting edges 24 on their outer surfaces. The bars 17 shown in Figures 3, 4, and 7 are bars which do not have the recesses or notches, whereas the bars presented in Figures 5, 6, 8, and 9 are bars which have the cutting notches or recesses on their outer peripheries. Having both recesses 23 and cutting edges 24, this special arrangement of the disintegrating or cutting elements provides a saw-tooth shaped peripheral area. The parallel ribs 17 are held in place by longitudinal braces 25 which, preferably, are disposed at both sides and in the middle of each bar 17 as by a force or friction fit. The aforementioned clamping screws 19 pierce into the boreholes 22.

Ithas been found advisable to taper the ribs 17 in radial direction, i.e., towards the axis of rotation. Moreover, the distintegrating or cutting elements 24- are also preferably gradually narrowed contrary to the direction of rotation, as roughly indicated in Figures 8 and 9. As shown in Figure 2, disclosing the developed area of a screening drum, the cutting elements 24 can be arranged in rows inclined towards the drum axle, that is, the cutting edges 24 can be arranged in vertical alignment with each other on adjacent bars or can be olfset with respect to one another or adjacent bars. Furthermore, if desired, some grate bars 17, provided with cutting elements, and some grate bars 17, having none, can be mounted in staggered order. This is true also ofpthe various groups of combs already described above. This arrangement provides both absolutely uniform cutting action and uniform distribution of the disintegrating forces over the entire drum area, while, simultaneously, avoiding backups or large conglomerations.

It will be appreciated by reference to the drawings that Figures 2, 3, and 7 present grates 11 having bars 17, which bars have a plain peripheral configuration. The bars presented in Figures 5, 6, 7, and 8 are ones which have a saw tooth peripheral configuration. As, shown in Figure 2 wherein a schematic representation of the developed area of the drum is shown, the manner in which the bars having a saw tooth peripheral configuration and the bars having a plain peripheral configuration are used, is shown.

While a preferred embodiment of the invention has been illustrated and described, it will be understood that the invention is not limited thereto, but contemplates such modifications and other embodiments as may occur to those skilled in the art. Thus, the present invention encompasses other drum-shaped disintegrating and screening apparatus similar to those described above, in which the cutting elements include recesses, notches, slots, etc., that do not jut beyond the drum circumference, although the specific form of the invention previously recited and shown in the drawings is preferred.

We claim:

1. In apparatus for disintegrating and automatically screening coarse floating matter carried in a liquid, the combination of a cylindrical drum screen comprising: a plurality of arcuate grates, said grates comprising a plurality of arcuate bars disposed parallel to and spaced from one another whereby arcuate slots are'formed between adjacent bars,'and a plurality of combs each having a head portion and spaced teeth extending from said head portion, said plurality of combs being disposed in sets, said sets being arcuately'displaced from one another around said drum, wherein at least some of said bars have a sawtooth peripheral configuration and wherein said combs are disposed with the teeth thereon extending within said slots and with the head portion between adjacent teeth cooperating with the peripheries of said bars. 7

2. In apparatus for disintegrating and automatically screening coarse floating matter carried in a liquid, the combination-0f a cylindrical drum screen comprising: a plurality of arcuate grates, said grates comprising a plurality of arcuate bars disposed parallel to and spaced from one another whereby arcuate slots are formed between adjacent bars, said drum being vertically disposed and wherein some of said grates comprise a plurality of arcuate bars substantially all having a sawtooth peripheral configuration and wherein other of said bars comprise a plurality of arcuate bars substantially all having a plain peripheral configuration, and a plurality of combs each having a head portion andspaced teeth extending from said head portion, wherein said combs are disposed with the teeth thereon extending within said slots and with the head portion between adjacent teeth cooperating with the peripheries of said bars and wherein said grates comprising bars having a sawtooth peripheral configuration are disposed in staggered relation to said grates comprise bars having a plainconfiguration.

3. The structure defined'in claim 2 wherein said grates comprising a plurality. of bars having a sawtooth configuration are disposed adjacent to a grate comprising a plurality of bars having a plain peripheral configuration on all sides thereof within the drum and wherein said plurality of combs are disposed in sets, said sets being arcuately displaced from one another around'said drum.

References Cited in the file of this patent UNITED STATES PATENTS Nordell Oct. 13,1942 973 Grant Oct.18,: 1838 822,591 Dowding June 5, 1906 2,079,995 Hodgkins May 11, 1937 2,317,416 Stanley Apr. 27, 1943 2,322,922 Chase June 29, 1943 2,336,069 9 Chase Dec. 7, 1943 2,375,455 Wirts May 8, 1945 FOREIGN PATENTS 897,506 Germany Nov. 23, 1953 911,350 Germany May 13, 1954 185,210 Switzerland Oct. 1, 1936 515,708 Belgium Dec. 15, 1952. 

